1. Field of the Invention
The present invention relates to an answer phone system, in particular, to an answer phone system having an answer phone function disposed on an exchange side.
2. Description of the Related Art
Conventionally, telephone units that are subscriber terminal units used in homes and offices have an answer phone function. With the answer phone function, if a receiving party is absent, a voice message of a sending party is recorded and reproduced with a speech circuit. Since the cost of a semiconductor memory used to record a voice message is lowering and the storage capacity thereof is rising, such an answer phone function can be used with only a telephone unit as a terminal unit.
On the contrary, an answer phone system having an answer phone function disposed on the exchange side is known. Since a terminal unit has the above answer phone function, the answer phone system disposed on the exchanger is limited to emergency calls for special situations.
However, in recent years, the number of users of mobile terminal units such as portable telephone units that communicate using a mobile communication network has remarkably increased. Due to the characteristics of the mobile telephone units, the users frequently use the answer phone function. Although the mobile telephone network covers most urban areas, their uses are restricted from view points of safety and etiquette (in car and public transportation). In such situations, the users should use the answer phone system. In addition, since there are needs for reducing the size and weight of the mobile terminal units such as portable telephone units, it is necessary to omit an additional device that stores an answer phone voice message.
For that reason, the answer phone service of the mobile communication network for portable telephone units or the like is provided on the exchange side, not the terminal unit side. Thus, both the needs for reducing the size of the terminal unit and for preventing the service from deteriorating due to an increase of the uses of the service are satisfied.
FIG. 1 shows an outlined structure of a conventional answer phone system. The answer phone system has an answer phone function of a mobile telephone network for portable telephone units. The answer phone system is composed of a public telephone network, first to N-th exchanges 111 to 11N (where 1 less than M less than N; M and N are natural numbers), an answer phone unit 12, and a portable telephone position storing unit 13. The public telephone network 10 has a plurality of exchanges (not shown) that connect and switch lines of the network. The first to N-th exchanges 111 to 11N accommodate first to N-th radio base stations 141 to 14N, respectively. The radio base stations 141 to 14N recognize first to N-th portable telephone units 151 to 15N, respectively. The answer phone unit 12 totally manages voice messages for the answer phone functions of the first to N-th portable telephone units 151 to 15N. The portable telephone position storing unit 14 stores registered-position information that represents which registered portable telephone unit is positioned in the radio area of which radio base station. The registered-position information is frequently updated corresponding to a predetermined position registering process.
In the answer phone system, the user of each portable telephone unit sets up an answer phone on/off mode. When the user of the first portable telephone unit 151 has set up an answer phone off mode, a call from the N-th portable telephone unit 15N to the first portable telephone unit 151 is connected to the portable telephone position storing unit 13 through the N-th radio base station 14N, the N-th exchange 11N, and the public telephone network 10. As explained above, the portable telephone position storing unit 13 has registered the radio base station that manages the radio area of the pre-registered portable telephone unit. The portable telephone position storing unit 13 transmits the registered-position information that represents the first exchange 111 or the first radio base station 141 that accommodates the first portable telephone unit 151 as the receiving party to the N-th exchange 11N through the public telephone network 10 corresponding to the call from the N-th portable telephone unit 15N. With reference to the registered-position information, the N-th exchange 11N connects the call to the first exchange 111 that accommodates the first radio base station 141 through the public telephone network 10 so as to establish a communication path. Thus, the N-th portable telephone unit 15N can communicate with the first portable telephone unit 151.
When the user of the first portable telephone unit 151 has set up the answer phone on mode, a call from the N-th portable telephone unit 15N to the first portable telephone unit 151 is connected to the portable telephone position storing unit 13 through the N-th radio base station 14N, the N-th exchange 11N, and the public telephone network 10. The portable telephone position storing unit 13 has already registered the answer phone on mode of the first portable telephone unit 151. Corresponding to the call from the N-th portable telephone unit 15N, the portable telephone position storing unit 13 notifies the N-th exchange 11N that the first exchange 111 has been set up to the answer phone on mode through the public telephone network 10. Thus, the N-th exchange 11N is connected to the answer phone unit 12 through the public telephone network 10 so as to establish a communication path. Consequently, a voice message that has been input from the N-th portable telephone unit 15N is recorded and stored to the answer phone unit 12 so that the voice message can be reproduced by the first portable telephone unit 151.
In the case that the first portable telephone unit 151 has set up the answer phone on mode and the answer phone unit 12 has registered answer-phone information (voice message), when the user of the first portable telephone unit 151 reproduces the voice message registered in the answer phone unit 12, the user dials a pre-assigned telephone number with the first portable telephone unit 151 so as to issue an answer-phone-reproducing request to the answer phone unit 12. The answer-phone-reproducing request is transmitted to the portable telephone position storing unit 13 through the first radio base station 141, the first exchange 111, and the public telephone network 10 (transmission 16). The portable telephone position storing unit 13 stores registration-valid/invalid information of answer-phone information of the answer phone service as well as the registered-position information. The portable telephone unit position storing unit 13 notifies the first exchange 111 that answer-phone information has been registered (notification 1). When the first exchange 111 has received the notification 1, the first exchange 111 connects a communication path with the answer phone unit 12 that has totally registered answer-phone information (connection 18). The first exchange 111 transmits the voice information reproduced corresponding to the answer-phone information registered in the answer phone unit 12 to the first portable telephone unit 151 through the first radio base station 141 (transmission 19).
In such an answer phone system, since the user records and reproduces answer-phone information as a voice message through the public telephone network, he or she may be charged for a communication fee corresponding to the distance from the answer phone unit 12 and the user""s terminal unit. In particular, when the user uses the answer phone service through an international telephone line network, the user may be charged for an expensive fee. To solve this problem, a technology disclosed in Japanese Utility Model Registration No. 3052588 titled xe2x80x9cApparatus for Transmitting Voice Informationxe2x80x9d is known. In the technology, a telephone unit is used as an Internet terminal unit. Answer-phone information is obtained from a voice mail storing unit through a mail server of the Internet.
In the conventional answer phone system shown in FIG. 1, the user who wants to use the answer phone service must dial a predetermined telephone number to retrieve the registered voice message, which is a inconvenience for the user. Even in a restricted situation in a public transportation such as a train, the user tends to use his or her portable telephone unit to avoid the above inconvenience, which is not desirable from a view point of etiquette.
On the other hand, in the case that the use of a portable telephone unit is restricted in a public transportation, when the user turns off his or her portable telephone unit, he or she should use the answer phone service afterward. Whenever the user uses the answer phone service for a registered voice message, the user is charged for a communication fee. As a result, the user moreover tends to use the portable telephone unit even if the use is restricted (in a public transportation such as a train).
When the position of the portable telephone terminal is far from the answer phone unit, the user must pay a regular communication fee even for a one-way communication. Thus, even if a particular communication provider leases a line from another communication provider, the former must pay an unexpected transfer communication fee. Such an unreasonable situation should be solved.
A registered voice message is transferred from the answer phone unit to a terminal unit. When the transmission amount of information needed for an answer-phone-reproducing request is compared with the transmission amount of information needed for reproduced-voice information, the latter is extremely large. Therefore, the information transmission efficiency is low. This disadvantage will adversely affect the quality of the answer phone service in a situation of a drastic increase of the number of portable telephone subscribers.
In the technology disclosed in Japanese Utility Model Registration No. 3052588, although an answer phone service can be provided between particular subscriber telephone units, in addition to a rise of the system cost, it is impossible to substitute all conventional subscriber telephone units with Internet terminal units.
Therefore, an object of the present invention is to provide an answer phone system in which an answer phone service is accomplished at a low user cost and the information thereof is effectively transmitted.
According to a first aspect of the present invention, there is provided a system for transferring a message responding to an answer phone through a packet network, comprising: a first telephone unit for transmitting the message; a first exchange for receiving the message transmitted from the first telephone unit to transfer the message; a first answer phone-transferring function unit for receiving the message transferred from the first exchange to store the message; a second answer phone-transferring function unit for retrieving the message from the first answer phone-transferring function unit through the packet network to transmit the message; a second exchange for receiving the message transmitted from the second answer phone-transferring function unit to transfer the message; and a second telephone unit for receiving the message transferred from the second exchange.
The system for transferring a message responding to an answer phone through a packet network may further comprise third answer phone transferring function units; wherein the second answer phone transferring function unit broadcasts a request packet to the first answer phone transferring function unit and the third answer phone transferring function units to retrieve the message from the first answer phone-transferring function unit.
In the system for transferring a message responding to an answer phone through a packet network, if one or more of the third answer phone transferring function units have stored messages, the second answer phone transferring function unit retrieves the messages from the third answer phone transferring function units which have stored messages so that the second answer phone transferring function unit transmits all the messages retrieved.
The system for transferring a message responding to an answer phone through a packet network may further comprise a storing unit; wherein if the second exchange receives an answer-phone-startup request from the second telephone unit, the second exchange transfers the answer-phone-startup request to the storing unit; and wherein if the storing unit receives the answer-phone-startup request from the second telephone unit through the second exchange, the storing unit turns on an answer-phone-startup information for the second telephone unit.
In the system for transferring a message responding to an answer phone through a packet network, if the first exchange receives a call originated from the first telephone unit and designated to the second telephone unit, the first exchange inquires of the storing unit whether or not the answer-phone-startup information is turned on for the second telephone unit; and if the answer-phone-startup information is turned on for the second telephone unit, the first exchange establishes a connection for the transmission of the message from the first telephone unit to the first answer phone-transferring function unit.
In the system for transferring a message responding to an answer phone through a packet network, if the second exchange received an answer-phone-reproducing request from the second telephone unit, the second exchange establishes a connection for the transmission of the message from the second answer phone-transferring function unit to the second telephone unit.
The system for transferring a message responding to an answer phone through a packet network may further comprise a storing unit for storing a connection information of the first answer phone-transferring function unit and a connection information of the second answer phone-transferring function unit; wherein the first exchange obtains the connection information of the first answer phone-transferring function unit from the storing unit; and wherein the second exchange obtains the connection information of the second answer phone-transferring function unit from the storing unit.
According to a second aspect of the present invention, there is provided a method for transferring a message responding to an answer phone through a packet network, comprising: a step that a first telephone unit transmits the message; a step that a first exchange receives the message from the first telephone unit; a step that the first exchange transfers the message; a step that a first answer phone-transferring function unit receives the message from the first exchange; a step that the first answer phone-transferring function unit stores the message; a step that a second answer phone-transferring function unit retrieves the message from the first answer phone-transferring function unit through the packet network; a step that the second answer phone-transferring function unit transmits the message; a step that a second exchange receives the message from the second answer phone-transferring function unit; a step that the second exchange transfers the message from the second answer phone-transferring function unit; and a step that a second telephone unit receives the message transferred from the second exchange.
The method for transferring a message responding to an answer phone through a packet network may further comprise: a step that the second answer phone transferring function unit broadcasts a request packet to the first answer phone transferring function unit and third answer phone transferring function units to retrieve the message from the first answer phone-transferring function unit.
The method for transferring a message responding to an answer phone through a packet network may further comprise a step that if one or more of the third answer phone transferring function units have stored messages, the second answer phone transferring function unit retrieves the messages from the third answer phone transferring function units which have stored messages so that the second answer phone transferring function unit transmits all the messages retrieved.
The method for transferring a message responding to an answer phone through a packet network may further comprise: a step that if the second exchange receives an answer-phone-startup request from the second telephone unit, the second exchange transfers the answer-phone-startup request to a storing unit; and a step that if the storing unit receives the answer-phone-startup request from the second telephone unit through the second exchange, the storing unit turns on an answer-phone-startup information for the second telephone unit.
The method for transferring a message responding to an answer phone through a packet network may further comprise: a step that if the first exchange receives a call originated from the first telephone unit and designated to the second telephone unit, the first exchange inquires of the storing unit whether or not the answer-phone-startup information is turned on for the second telephone unit; and a step that if the answer-phone-startup information is turned on for the second telephone unit, the first exchange establishes a connection for the transmission of the message from the first telephone unit to the first answer phone-transferring function unit.
The method for transferring a message responding to an answer phone through a packet network may further comprise: a step that if the second exchange received an answer-phone-reproducing request from the second telephone unit, the second exchange establishes a connection for the transmission of the message from the second answer phone-transferring function unit to the second telephone unit.
The method for transferring a message responding to an answer phone through a packet network may further comprise: a step that a storing unit stores a connection information of the first answer phone-transferring function unit and a connection information of the second answer phone-transferring function unit; a step that the first exchange obtains the connection information of the first answer phone-transferring function unit from the storing unit; and a step that the second exchange obtains the connection information of the second answer phone-transferring function unit from the storing unit.